function Model(){

	var numExtraVertexArgs = 3;
	
	this.pushVertex = function(vert, normal, extraVertex) {
		//if (arguments.length < 2) normal = [0, 0, 0];
		if (arguments.length < 3) extraVertex = [];

		while (extraVertex.length < numExtraVertexArgs) extraVertex.push(0);

		this.vertexData.push(vert[0], vert[1], vert[2]);
		this.normalData.push(normal[0], normal[1], normal[2]);
		this.extraVertexData.push(extraVertex[0], extraVertex[1], extraVertex[2]);
	}

	this.mvMatrix = mat4.create();
	/*
	var mvMatrixStack = [];
	function mvPushMatrix() {
		var copy = mat4.create();
		mat4.set(mvMatrix, copy);
		mvMatrixStack.push(copy);
	}
	function mvPopMatrix() {
		if (mvMatrixStack.length == 0) {
			throw "Invalid popMatrix!";
		}
		mvMatrix = mvMatrixStack.pop();
	}
	*/

	setDefaults(this);
}
